1. Field of the Invention
The invention relates to a composite structure, comprising a rod whose outer profile is circular or anyhow curvilinear and preferably tubular, and a collar locked on the rod and composed of two semicollars, which have lateral longitudinal flanges projecting outwards, and are clamped to each other and locked on the rod by means of bolts or other clamping systems, passed through the flanges associated to each other, each flange of each semicollar being delimited by two surfaces which are substantially plane-parallel, one, the so-called inner one, which faces the associated flange of the other semicollar, and the other opposite, the so-called outer one, whereas the substantially semicylindrical inner surface of at least one of the semicollars extends--in cross section--over a circular arc of less than 180.degree. between the inner surfaces of the two flanges of the corresponding semicollar. Another object of the invention is a method for assembly of this composite structure, that is a method for mounting the collar on its respective rod, as well as a preferred use of the composite structure itself.
2. Prior Art
In prior art composite structures of this type, the flanges of each semicollar are not directly touching those of the other collar and, on mounting, the prescribed distances between the inner surfaces of the two pairs of flanges must be respected. Namely, this type of collar must be mounted in such a way that, in the mounted condition of the collar, the facing inner surfaces of the flanges of the two semicollars, tightened by means of clamping bolts, must be substantially parallel to each other and properly spaced. Only in this case, the axes of the clamping bolts are disposed so as to be substantially perpendicular to their respective flanges, fixed to each other, of the semicollars, whereas the heads and the nuts--or the corresponding washers--adhere substantially with the whole of their bearing surface to the corresponding outer plane surfaces of the flanges. However, this position of the two semicollars while tighthened and locked on its respective rod is very difficult to achieve in practice or requires a long and tiring mounting work, consisting, for example in the tightening of the clamping bolts on the two sides of the collar alternately each time of a small step, trying to keep the flanges of the two semicollars parallel and properly spaced. Frequently, on mounting of the collar on the rod, the flanges of the semicollars on one side of the collar are tightened and approached to each other to a larger extent than the flanges of the collars on the opposite side. Consequently, the substantially complanar flanges of one of the semicollars and the substantially complanar flanges of the other semicollar are slanted towards each other on both sides of the collar and the axes of the clamping bolts are no longer perpendicular to at least one of their two respective linked flanges, and so the head and/or the nut (or their respective washers) of the clamping bolts adhere to the corresponding outer surfaces of their respective flanges no longer with the whole of their bearing surface but only locally, with a portion of it. This generates high local specific pressures, and the danger of deformations and/or of an incomplete and/or not uniform and/or asymmetric adhesion of the inner surface of the collar against the corresponding outer surface of the rod, which can finally compromise the firm and safe locking of the collar on the rod.
The invention is aimed at eliminating the aforesaid drawbacks and at providing a composite structure of the type described hereinbefore, in which the collar may be mounted on the rod in an easier and faster way; ensuring in an easy and substantially automatic manner the axes of the clamping bolts to be always substantially perpendicular to their respective flanges of the semicollars on both sides of the latter, and thus the said bolts to adhere substantially with the whole of the bearing surface of their heads and of their nuts (or of their respective washers) against the outer surfaces of the corresponding pairs of flanges linked to each other.